Thalamic activity, and ultimately cortical processing, is strongly affected by fluctuating subthreshold membrane potential levels in the thalamus, or the thalamic state. It has long been posited that hyperpolarizing the thalamus will lead to a 'burst' firing mode while depolarizing the thalamus will lead to a 'tonic' firing mode. Although we have some knowledge of the firing modes induced by thalamic state, we do not have a clear understanding of how these firing modes affect the transmission of sensory information. Previous work in our lab has suggested that the 'burst' mode may be indicative of a 'detect' mode while a 'tonic' mode may be better suited for a 'discrimination' mode. In this work, I plan to comprehensively examine the role of imposed thalamic states on the encoding of somatosensory information in the rat whisker pathway. By manipulating thalamic state using optogenetic methodologies, I will be able to explicitly test hypotheses about the relationship between firing mode and information transmission in anesthetized and awake behaving animals. The results of this work could have multiple clinical applications. The thalamus is a critical structure implicated in both sensory and motor function. An understanding of how to manipulate the state of the thalamus to achieve a desired level of information transmission could lead to improved sensory prosthetics, alternative thalamic pain relief methodologies, or restorative motor control. The role thalamic state on information flow could be extended to other brain regions, permitting alternative methods of controlling information flow in clinical applications such as deep brain stimulation. A more complete understand of how the constantly fluctuating state of the thalamus, and the brain, is affecting the transmission of information is critical for he clinical success of engineered applications.